Archive for November, 2006



Online Event – Ocean Acidification

On November 13th-14th, 2006, The World Ocean Observatory will present an online, interactive web-cast on Ocean Acidification. This is a unique opportunity for students, educators and interested individuals to participate in the first demonstration of an ongoing series of global online events to explore ocean issues. Those who attend this 45 minute event hosted in Australia will participate in a real-time interactive presentations and discussions with leading scientists around the world.

More information: The World Ocean Observatory

Effects of anthropogenic seawater acidification on acid–base balance in the sea urchin Psammechinus miliaris

The purple-tipped sea urchin, Psammechinus miliaris, was exposed to artificially acidified seawater treatments (pHw 6.16, 6.63 or 7.44) over a period of 8 days. Urchin mortality of 100% was observed at pHw 6.16 after 7 days and coincided with a pronounced hypercapnia in the coelomic fluid producing an irrecoverable acidosis. Coelomic fluid acid–base measures showed that an accumulation of CO2 and a significant reduction in pH occurred in all treatments compared with controls. Bicarbonate buffering was employed in each case, reducing the resultant acidosis, but compensation was incomplete even under moderate environmental hypercapnia. Significant test dissolution was inferred from observable increases in the Mg2+ concentration of the coelomic fluid under all pH treatments. We show that a chronic reduction of surface water pH to below 7.5 would be severely detrimental to the acid–base balance of this predominantly intertidal species; despite its ability to tolerate fluctuations in pCO2 and pH in the rock pool environment. The absence of respiratory pigment (or any substantial protein in the coelomic fluid), a poor capacity for ionic regulation and dependency on a magnesium calcite test, make echinoids particularly vulnerable to anthropogenic acidification. Geological sequestration leaks may result in dramatic localised pH reductions, e.g. pH 5.8. P. miliaris is intolerant of pH 6.16 seawater and significant mortality is seen at pH 6.63.

Miles et al., in press. Effects of anthropogenic seawater acidification on acid–base balance in the sea urchin Psammechinus miliaris. Marine Pollution Bulletin. Article.

Dropping pH in the Oceans Causing a Rising Tide of Alarm

One of the most unexpected consequences of global climate change may well turn out to be one of the most severe in terms of impacts on life on earth. As continued carbon emissions accelerate global warming, the carbon dioxide contained in those emissions is able to silently yet dramatically reduce the alkalinity of the oceans. And as the pH drops, marine organisms that produce shells and carbonate skeletons grow weak and die off.

The discovery that carbon dioxide emissions can lower global ocean pH is very recent, even though chemists and biologists have for long known that when carbon dioxide dissolves in water, carbonic acid results. However, the sheer volume of water in the oceans has always been assumed to be so vast as to be safe from changes in chemical balance brought about by small scale inputs. In effect, it is just plain hard to imagine that atmospheric inputs of any kind could significantly alter the chemical composition and nature of over 1.3 trillion cubic kilometers of ocean water. Thus when intrepid oceanographers and marine ecologists set out to address the question of how changing atmospheric conditions that lead to changes in pH could affect marine life, they raised alarms about the possibilities of very large scale impacts.

Tundi Agardy, The W2O Observer. Article.

Apocalypse now

Sir Nicholas Stern was commissioned by British Chancellor Gordon Brown to write a landmark report on climate change, amid growing fears about the human and economic cost of global warming. Stern, an internationally regarded economist, spent more than a year examining the complex problem. After a week of rumours and leaks, on October 30 he formally launched his 579-page report. Though dry in its delivery, it had a simple and apocalyptic message: climate change is fundamentally altering the planet; the risks of inaction are high; and time is running out. This is a summary of the key findings.

David Adam and Larry Elliott, Mail & Guardian Online, 2 November 2006. Article

Scandal below the surface

By NICHOLAS D. KRISTOF

The New York Times, 31 October 2006. Article.
The crucial issue this year is Iraq, and the most important issue this decade may be the risk that nuclear proliferation results in the incineration of Wall Street by terrorists. Both topics are spurring useful debate this campaign season.

But one of the more important issues this century is generating no serious discussion on the campaign trail. And, in place of a drumroll, let’s look at the chemistry experiment in which we’re all taking part.

If you think of the earth’s surface as a great beaker, then it’s filled mostly with ocean water. It is slightly alkaline, and that’s what creates a hospitable home for fish, coral reefs and plankton — and indirectly, higher up the food chain, for us.

But scientists have discovered that the carbon dioxide we’re spewing into the air doesn’t just heat up the atmosphere and lead to rising seas. Much of that carbon is absorbed by the oceans, and there it produces carbonic acid — the same stuff found in soda pop.

That makes oceans a bit more acidic, impairing the ability of certain shellfish to produce shells, which, like coral reefs, are made of calcium carbonate. A recent article in Scientific American explained the indignity of being a dissolving mollusk in an acidic ocean: “Drop a piece of chalk (calcium carbonate) into a glass of vinegar (a mild acid) if you need a demonstration of the general worry: the chalk will begin dissolving immediately.”

The more acidic waters may spell the end, at least in higher latitudes, of some of the tiniest variations of shellfish — certain plankton and tiny snails called pteropods. This would disrupt the food chain, possibly killing off many whales and fish, and rippling up all the way to humans.

We stand, so to speak, on the shoulders of plankton.

“There have been a couple of very big events in geological history where the carbon cycle changed dramatically,” said Scott Doney, senior scientist at the Woods Hole Oceanographic Institution in Massachusetts. One was an abrupt warming that took place 55 million years ago in conjunction with acidification of the oceans and mass extinctions. Most scientists don’t believe we’re headed toward a man-made variant on that episode — not yet, at any rate. But many worry that we’re hurtling into unknown dangers.

“Whether in 20 years or 100 years, I think marine ecosystems are going to be dramatically different by the end of this century, and that’ll lead to extinction events,” Mr. Doney added.

“This is the only habitable planet we have,” he said. “The damage we do is going to be felt by all the generations to come.”

So that should be one of the great political issues for this century — the vandalism we’re committing to our planet because of our refusal to curb greenhouse gases. Yet the subject is barely debated in this campaign.

Changes in ocean chemistry are only one among many damaging consequences of carbon emissions. Evidence is also growing about the more familiar dangers: melting glaciers, changing rainfall patterns, rising seas and more powerful hurricanes.

Last year, the World Health Organization released a study indicating that climate change results in an extra 150,000 deaths and five million sicknesses each year, by causing the spread of malaria, diarrhea, malnutrition and other ailments.

A report prepared for the British government and published yesterday, the Stern Review on the Economics of Climate Change, warned that inaction “could create risks of major disruption to economic and social activity, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century.”

If emissions are not curbed, climate change will cut 5 percent to 20 percent of global G.D.P. each year, declared the mammoth report. “In contrast,” it said, “the costs of action — reducing greenhouse gas emissions to avoid the worst impacts of climate change — can be limited to around 1 percent of global G.D.P. each year.” Some analysts put the costs of action higher, but most agree that it makes sense to invest far more in alternative energy sources, both to wean ourselves of oil and to reduce the strain on our planet.

We know what is needed: a carbon tax or cap-and-trade system, a post-Kyoto accord on emissions cutbacks, and major research on alternative energy sources. But as The Times’s Andrew Revkin noted yesterday, spending on energy research and development has fallen by more than half, after inflation, since 1979.

Melting glaciers and corroding pteropods aren’t as sensational as a Congressional page scandal, or as urgent as the Iraq war. But they are just as scandalous. We have no responsibility greater than as stewards of our planet, and we’re blowing it.

We’ll pay the price later for abusing Earth now

… But one of the more important issues this century is generating no serious discussion on the campaign trail. And in place of a drumroll, let’s look at the chemistry experiment in which we’re all taking part.

If you think of the earth’s surface as a great beaker, then it’s filled mostly with ocean water. It is slightly alkaline, and that’s what creates a hospitable home for fish, coral reefs and plankton — and indirectly, higher up the food chain, for us. But scientists have discovered that the carbon dioxide we’re spewing into the air doesn’t just heat up the atmosphere and lead to rising seas. Much of that carbon is absorbed by the oceans, and there it produces carbonic acid — the same stuff found in soda pop. That makes oceans a bit more acidic, impairing the ability of certain shellfish to produce shells

Kansas City Star, 1st November 2006. Article.

Under-threat coral reefs get protection strategy

A new report has outlined a strategy to protect the world’s declining coral reefs. Covering just 0.2 per cent of the ocean floor, the reefs are home to 25 per cent of marine species globally. They also provide livelihoods to 100 million people and the basis for industries such as tourism and fishing, which are worth an annual net benefit of $US 30 billion (£16 billion). But climate change is threatening these tropical ecosystems; 20 per cent have already been wrecked and a further 50 per cent are facing immediate or long-term danger of collapse due to increases in sea temperature and ocean acidification.

inthenews.co.uk, 1st November 2006. Article.

Building Resilience May Help Corals, Mangroves Survive

GENEVA, Switzerland, October 31, 2006 (ENS) – Survival strategies for coral reefs and mangroves threatened by climate change are outlined by scientists of IUCN-World Conservation Union and the Nature Conservancy in two new publications launched today. The strategies rely on managing stressors other than global warming so that corals and mangroves are more resilient and able to survive in a warming world.

Climate change is destroying tropical marine ecosystems through sea temperature increase and ocean acidification. Scientists say 20 percent of the world’s coral reefs have already been ruined and a further 50 percent are facing immediate or long term danger of collapse.

Environment News Service, 1st November 2006. Article.


Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,426,244 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book

Archives